Basement Waterproofing for local leisure centre development

Client: GTCI Ltd

Products Used: MS500 Cavity Drain Membrane

MS20 Floor Membrane

Vandex BB75E

Perimeter Drainage Channel

Pumping Stations


Constructed almost 50 years ago, and built from a traditional dark red high-density brick, the two storey building in question had a very large below ground void that had become increasingly affected over the years by water ingress.

The basement level was not in use but had previously been a health suite with plant and storage rooms. The walls have been rendered with dense sand and cement and the floors overlaid with concrete. High moisture levels were recorded in several locations with high levels of salt contamination to the skim plaster. Timberwise were tasked to design and install a basement waterproofing system due to the property being converted into a leisure centre with accompanying swimming pool.

The Waterproofing Design Methodology

Based on a poor previous experience the client did not want any form of internal cementitious render waterproofing, however, they were aware of the existence of cavity drain membrane systems. The client was therefore very receptive to Timberwise’s proposal of a complete wall and floor cavity drain membrane solution alongside a perimeter drainage channel and four subfloor sump and pump chambers.

Before Timberwise could commence work, a full specification of preparation works was carried out by the builder for Timberwise to seamlessly install the necessary waterproofing system. The lower basement and pool area was waterproofed using a special cavity drainage membrane and special plugs to allow it to be finished either by a freestanding plasterboard system or with a freestanding mesh block wall built in front.

Furthermore, due to the size of the system and evidence of natural deposits within the underlying water table, Timberwise incorporated regular inspection points within the channel to allow easy access for servicing.

Once the system had been installed and electrically commissioned Timberwise undertook a flood test to demonstrate to the client first hand, that water flowed away freely and that all of the sumps and pumps operated as planned – pumping water to the designated outlets and into the accompanying drainage. The customer, via their own contractor, was able to finish the internal installation by way of dry lining and decorating, thus creating a dry warm and habitable belowground environment.

 This new leisure centre will serve all local residents. We’re proud to be part of the waterproofing design and installation team to support healthy lifestyles and compliment the growth of the area for years to come 

Keith Defoe, Waterproofing Design Specialist CSSW

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